Atari 8-bits & Linux EmulatingEmulating andand enhancingenhancing realreal AtariAtari 8-bit8-bit hardwarehardware usingusing LinuxLinux BillBill KendrickKendrick LinuxLinux Users'Users' GroupGroup ofof DavisDavis AugustAugust 19,19, 20132013 What were they? Overview ● 1979 – 1992 ● Similarities to Atari VCS (2600) before it, and Commodore Amiga after it (Jay Miner involved in all three) ● 6502 8-bit CPU @ 1.79MHz ● 64KB RAM (expandable to 4MB), 10KB OS ROM ● Cartridge slot (lots of games!) ● Serial I/O with daisy-chain support (Later models included Parallel Bus Interface) ● Cassette, floppy disk ($) and hard drive ($$$) storage What were they? Gfx & Sfx ● 4-channel mono sound (8-channel stereo hacks exists) ● Graphics reat graphics (for those days) – Various bitmapped & text modes with user-definable character sets (fonts) ● 320x192 high resolution monochrome ● 40x24 thru 160x192 4-color bitmap modes ● 40x24 mono and multicolor character modes ● 20x24, 20x12 color, but not-multicolor char ● Coarse & fine scrolling ● Graphics chip has Direct Memory Access; can be changed on a per-scanline basis (e.g., part of the screen scrolls through a larger area, the rest stays static) ● Modes can be set on a per-scanline basis (Display List) (e.g., graphics with a text 'window' at the bottom) ● Per-scanline interrupts can be set (Display List Interrupts) (e.g., change color palette, change font, reposition sprite, change scroll values, etc.) – “Player/Missile Graphics” (aka sprites); overlay, underlay, mix ● Hardware collision detection – 128 color palette; 256 possible – What were they? Photos! What were they used for? ● Games ● Education ● Home office ● Programming ● Games Emulating on Linux ● Atari800 - http://atari800.sourceforge.net/ ● MESS - http://www.mess.org/ ● JavaScript MESS (beta) http://jsmess.textfiles.com/messbeta.html?module=a800 ● Windows-based emulators (under virtualization) might work too! – Altirra - http://www.virtualdub.org/altirra.html – Atari800Win PLus - http://atariarea.krap.pl/PLus/index_us.htm ● Many more... Getting OS ROM Before Atari Corp. reverse-merged with JTS, it gave Darek Mihocka (Emulators, Inc.) permission to include Atari OS and BASIC ROMs with his “PC XFormer” emulator for MSDOS. They can be retrieved from a demo version of PCXF that was made available. e.g.: http://sourceforge.net/projects/atari800/files/ROM/ There were other OS ROMs back in the day, and new alternatives today, as well... Getting Software ● Warning: Much software is available for download, but often not legitimately. ● However, tons of public domain (and these days, even open source) software is available, with more released every year! ● Try, for example: – http://www.atarimania.com/atari-400-800-xl-xe.html – http://atariage.com/forums/forum/12-atari-8-bit-computers/ Getting Information ● Atari Archives - http://www.atariarchives.org/ – Contents of classic books, posted with permission from copyright holders ● Classic Computer Magazine Archive - http://www.atarimagazines.com/ – Ditto, but for magazines (sister site); more than Atari, now ● AtariAge - http://atariage.com/ – News & forums (all Atari, not just 8-bit) ● Tip of the iceberg... so much more, I don't know where to begin Real Atari + Linux #1 – SIO2SD ● External device with an SD card reader, Atari SIO cable, small back-lit display, and navigation/control buttons ● The Atari sees it as a series of floppy disks (that is, the Atari doesn't need to be modified) ● Use Linux (or Win or Mac) to load up SD card with disk images (e.g., “.atr”) or executables (that you'd normall load from a DOS on the Atari; SIO2SD will provide bootstrap!) ● I bought an SIO2SD for $70 from Poland Real Atari + Linux #1 – SIO2USB ● External device with USB connection, Atari SIO cable, small back-lit display, and navigation/control buttons ● The Atari sees it as a series of floppy disks ● Also has built-in realtime clock the Atari can use ● Similar to SIO2SD, but uses any USB mass storage device Real Atari + Linux #2 – SIO2PC ● Connects Atari to PC via serial or USB ● The Atari sees PC as a series of floppy disks, and can also show up as printer, RS232 (e.g. modem) ● (SIO2SD & SIO2USB are basically stand-alone embedded solutions based on this older concept; it dates back to earl 1990s, the MSDOS days!) ● Use with: – atarisio (text mode for Linux) – AspeQt (GUI for Linux/Windows) – SIO2PC (text mode for MSDOS) – APE (GUI for Windows) (supports backing up and emulating copy-protected Atari disks, with ProSystem cable) Real Atari + Linux #3 – MaxFlash ● Cartridge with flash memory ● Load with cartridge ROM dumps, or disk images or executables; doesn't work over SIO, so some games/apps won't be compatible ● Cart plugs into USB widget, or just use the Atari to program it directly! ● Use USB widget with a Perl command-line tool (Linux), or GUI tool (Windows) http://www.atarimax.com/flashcart/documentation/ Real Atari + Internet ● Atari → SIO2PC → Linux, emulating RS232 ● Atari → real RS232 device (e.g., Atari 850, P:R:Conn. ($)) → RS232-to-ethernet (e.g., Lantronix UDS-10 ($$$)) ● There are BBSes running on Atari 8-bits that you can telnet into over the Internet! Real Atari + Internet, no middleman ● Dragon Cartridge - http://www.atari8ethernet.com/ Cross-assembly on Linux ● ATasm - http://atari.miribilist.com/atasm/ “a mostly Mac/65 compatible cross-assembler” ● xasm - http://atariarea.krap.pl/x-asm/ originally written as a Quick Assembler replacement ● MADS - http://mads.atari8.info/ multi-pass crossassembler for 6502 & 65816 processors ● ca65 - http://oliverschmidt.github.io/cc65/doc/ca65.html The “cc65” C cross compiler's own cross-assembler (can be used on its own) ● Undoubtedly a number of others! ● Also check out 6502 Source Code Repository - http://www.6502.org/source/ Cross-compiling on Linux - C ● cc65 – Complete cross development package macro assembler, C compiler, linker, librarian & other tools – Originally based on cc65 for the Atari itself – Was: http://www.cc65.org/, but no longer maintained as of March 2013! – Now: http://oliverschmidt.github.io/cc65/ Cross-compiling on Linux – C - Example /* hiworld.c */ CC65_HOME=/usr/local/lib/cc65 #include <stdio.h> all: hiworld.xex #include <unistd.h> clean: int main(void) { -rm hiworld.xex -rm hiworld.o int i; hiworld.xex: hiworld.c printf("Hello, world.\n"); cl65 -t atari hiworld.c mv hiworld hiworld.xex sleep(2); run: hiworld.xex for (i = 0; i < 1000; i++) { atari800 -nobasic -run hiworld.xex printf("."); } return(0); } Cross-compiling on Linux – Action! ● Action! was an integrated editor, compiler, and debugger on a cartridge. High-level code, but still very fast. Syntax similar to ALGOL 68. ● Projects to create Action! cross compilers: – Effectus - http://gury.atari8.info/effectus/ Uses MADS assembler – Another: http://www.noniandjim.com/Jim/atari/Action_Compiler.html Some older new games... ● Gem Drop (1998) Action puzzle, based on “Magical Drop III” arcade game. (Written by your's truly in Action!; ported to C + libSDL for Linux & other modern platforms, as “Gem Drop X”) http://www.newbreedsoftware.com/gemdrop/ ● Castle Crisis (2003) Based on “Warlords” arcade game. (Basically, multiplayer “Breakout”) http://www.atarimania.com/game-atari-400-800-xl-xe-castle-crisis_19788.html ● Beef Drop (2004) Based on “Burger Time” arcade game. http://www.atarimania.com/game-atari-400-800-xl-xe-beef-drop_12157.html Some recent new games... ● His Dark Majesty (2010) Turn-based strategy. (Cross-compiled C!) http://hdm.atari.pl/ ● Tempest Xtreem (2008) Updated version of Tempest arcade game, that plays more like Tempest 2000 Atari Jaguar game http://members.tcq.net/video61/tempest1.html ● Crownland (2007) Scrolling jump-and-run game ● Yoomp! (2007) 3D action puzzle http://yoomp.atari.pl/ Newest new games... ● Pac-Man Arcade (2012) Conversion of 1980s “Ms. Pac-Man” by Atari to a more arcade-perfect version of original “Pac-Man” than the 1980s “Pac-Man” by Atari ● Ridiculous Reality (2012) Puzzle jump-and-run game based on mobile game “Continuity” http://matosimi.websupport.sk/atari/2012/10/ridiculous-reali ty/ ● Asteroids emulator (2012) Original arcade game was 6502, so this emulates the rest of the hardware on Atari 8-bit http://web.utanet.at/nkehrer/ast800xl.html ● Line Runner (2012) Version of a popular Android/iPhone game http://gr8.atari.pl/joomla/ New Atari Hardware (not Linux-related, but interesting) ● Incognito board Turn an Atari 800 into an XL-compatible, and then some! (64KB (vs 48K) accessible RAM, 1MB installed; Parallel Bus Interface; CompactFlash storage; SpartaDosX; Real Time Clock) http://spiflash.org/index.php/block/29.html ● VBXE FPGA-based video upgrade http://spiflash.org/block/15.html ● SIDE2 Cartridge providing Compact Flash drive, SpartaDosX, Real Time Clock http://spiflash.org/block/16.html Conclusion ● Atari 8-bits have a 35 year history ● Tons of activity in the early days, then a lull, and now a resurgence – FPGAs, cheap manufacturing, fast modern PCs – Internet: forums, chat rooms, YouTube, archives ● Easy to dip your toes in (play some Pac-Man) ● Going deeper, hardware & software choices abound! – Too much for a mini-talk; most beyond my experience level, anyway .